Piano action



` c. F. sMrrH PIANO ACTION April' 5, 1949.

vFilm1 Jan. 1o, `1947 me l nu. um.

www,

Patented Apr. 5, 1949 UNITED STATES PATENT OFFICE PIANO ACTION CharlesF. Smith, Forest Park, Ill. Application January 10, 1947, Serial No.721,195

6 Claims. (Cl. 84-239) The present invention relates to piano actions,and more particularly to a, grand piano action for the bass section ofthe piano.

While the escapement of the piano actions was improved by theintroduction of the repetition lever more than a century ago, thiscombination has remained substantially the same. The professionalpianist develops suiiicient linger strength and endurance to play forlong periods, and does not demand any improvement in the vpiano action.The very young players and the average adult players however do not havethe power to play for long periods because the action is too heavy orstiff. Consequently some efforts have been made to correct this by theuse of counterweights and springs, but at present according to theauthorities the usual piano key will be depressed slowly by a weight of50 grams and will return and lift about 17 grams. A reduction in thedifference between the amount of weight required to depress the key andwhat it will lift will produce a better piano action requiring less ngerpower. The dynamic range will be greatly extended and the speed ofoperation will be much higher.

Because of the manner in which the piano action is located in grandpianos, the actions employed by dilerent piano manufacturers of grandpianos are substantially the same. The location of the piano actionrequired by the construction of the grand piano is such that in generalthe touch of the piano keys of a grand piano is much heavier than thatof an upright piano, This difference in the touch between the two pianoconstructions is particularly noticeable in the bass section. In orderto properly balance the piano action in the bass section variouscounterbalance weights have been inserted in the piano keys. While thisproduces a balancing action, it also increases the inertia so that thekeys in the bass section of the piano cannot be actuated at the samerate of speed as the keys in the treble section.

It therefore would be desirable to provide an improved piano actionparticularly suited for the bass portion of a grand piano which wouldhave a lighter touch. In accordance with the present invention this isaccomplished by two structural features. The one feature employs aspring associated with the hammer stem to lighten the weight of thehammer. The other feature employs an improved support for the knuckle ofthe hammer stem or hammer butt. By means of these two featuredconstructions it is possible to provide an improved piano actionparticularly of advantage in use in the bass section which has reducedfriction and a lighter touch.

It is therefore an object of the present invention to provide animproved piano action having a relatively light touch and a high speedof return for the key.

A further object of the lpresent invention is to provide an improvedconstruction which will minimize the friction in the piano action,particularly between the hammer knuckle and the remainder of the pianoaction.

A still further object of the present invention is to provide anarrangement for reducing the ef. fect of the weight of the hammer inrepetition of the sounding of a note.

A still further object of the present invention is to provide a springarrangement for supporting the weight of the hammer which spring doesnot require detachment in order to raise the hammer for access to theadjustment of the piano action.

A still further object of the present invention is to provide animproved grand piano action which reduces the inertia of the action ascompared to the present employed construction.

Other and further objects of the present invention subsequently willbecome apparent by reference to the following description taken inconjunction with the accompanying drawing where- 1n:

Fig. l is a fragmentary side elevation of a grand piano escapementaction;

Fig. 2 is a fragmentary perspective view of the hammer butt;

Fig. 3 is a partial view of the hammer butt and stem illustrating themanner of supporting the knuckle;

Fig. 4 illustrates the knuckle in action; and

Fig. 5 is a cross sectional View as seen in the direction of the arrowsalong the 5-5 of Fig. 3.

Referring more particularly to the drawing it will be seen that therehas been shown a key frame or base I I which carries a plurality offront key pins I2 each of which is surrounded by a felt washer I3. Thebase II also carries a balance rail I4 which supports a plurality ofbalance key pins I5. The keys I6 are held in position by the balancepins I5, and the keys rest upon felt washers Il. The back end of each ofthe keys I6 carries a felt pad I8 adapted to engage the damper leverwhich is carried by the damper action bracket or frame I9.

At an intermediate point between the rear extremity of the key I6 andthe balance key pin I5, each key I6 is provided with a capstan screw 2|.The capstan screw 2| bears against a felt surface 22 carried by adepending portion 23 of a whip or whippen 24. The whippen 24 is suitablysupported at its rear end by a whip flange 25 which is secured by ascrew 26 to a whip rail 2l. The whip rail 21 is held in position by awhip rail bracket screw and washer 28 which is secured to the whipflange portion of the action bracket or frame 29. The outer extremity ofthe whip 24 is connected to an intermediate point on the jack 3| whichat an intermediate point carries a jack regulating 3 screw 32. The screw32 has a jack butt 33 which rests against the whip spoon 34.

The bell crank extremity of the jack 3| is arranged to engage theregultaing button 35 carried by the regulating rail 36 by means of aregulating rail screw 31.

The whip 24 at an intermediate point carries a repetition lever ange 38which is pivotally connected at an intermediate point to a repetitionlever 39. One extremity of the repetition lever 39 carries a repetitionlever regulating screw 4| which in turn carries a repetition leverregulating button 42. The button 42 rests upon a felt pad adjacent therear pivotal connection of the whip 24. The repetition lever 39 carriesa repetition vlever spring 43 which engages a loop 44 which is securedto the whip 24. A suitable adjusting set screw is provided for adjustingthe tension of the repetition lever spring 43. Adjacent the outer orforward extremity of the repetition lever 39 there is an aperturethrough which passes the upper extremity of `the jack 3|. Both the jack3| and the repetition lever 39 engage a knuckle 45 which is carried bythe hammer butt 46. The hammer butt 46 is pivotally connected to a buttflange 4l which is mounted in position by a screw 48 upon a butt rail 49carried by the forward or front portion of the action frame 29. Thehammer butt 45 extends rearwardly to a reduced diameter portion known asa hammer stem The hammer stem 5| carries at its outer extremity a hammer52 which when raised to the dotted line position will strike and engagethe piano string 53. When a key is struck and held down the back check54 carried at the rear end of the key I6 comes into action to limit thedownward motion of the hammer 52.

The parts thus far described without reference to any particular type ofstructure constitute the common grand piano action, with the exceptionof the fact that particularly in the bass section each of the keys I6 isnormally provided with from one to ve weights in that portion of the keyextending forwardly of the balance key pins I5.

In accordance with the present invention the usual grand piano action ismodied in accordance with the structure shown in detail in Figs. 2, 3, 4and 5.

The butt 46 carries a knuckle 45 which usually is fastened rigidly withrespect to the butt 45. In accordance with the present invention howeverthe knuckle 45 is mounted on a transverse pin member 55 held in positionby a pivot pin 56. As is customary the knuckle 45 is generally coveredby a piece of firm felt 5l. From the construction shoivn in Figs. 2 to 5it is apparent that the support block 55 is capable of limited pivotalmovement with respest to the butt 46. As may be seen from Fig. 5 theextremities of the pin 56 may be supported in suitable bearing portions58.

The purpose of providing for limited pivotal movement of the knuckle 45of the butt 4E of the hammer is to reduce the amount of frictionoccurring in the relative movement of the hammer and the remainder ofthe piano action. When the hammer which has been raised returns towardits original position it engages the repetition lever and jack to causethe key |6 to be raised. The engagement of the knuckle 45 with therepetition lever and jack produces a motion of the knuckle 45 in thedirection illustrated in Fig. 4 whereby the knuckle moves toward thehammer 52. When the key I6 is depressed,

the knuckle remains in contact with the repetition lever and jackwithout any sliding action thus greatly reducing the friction at thispoint of contact. This construction preferably is employed in both thebass and treble portions of the piano.

In the position shown in Fig. 1 the hammer stem 5| rests upon a feltmember 59 which is carried by the hammer support 6|. Where a hammer railis employed instead of individual supports, the felt member 59 is astrip which is notched or grooved so as to receive and hold in positionthe rear extremity of a spring 62. Into these notches then is tted therear extremity of the spring 62. Where individual supports 6| areemployed the hammer rest is provided with a suitable pin 63 forsupporting one extremity of the spring 62. The spring 62 extendssubstantially the greater portion of the length of the stern 5l up tothe butt portion 45. There the spring is wound into a coil 64 ofsuiiicient power that its effect upon the raising hammer 52 is verynearly constant throughout the movement of the hammer toward the string53.

From the coil 64 the spring continues up through a suitable aperture inthe butt 46 and across the top surface thereof and back down throughanother aperture until the end of the spring 55 terminates on the bottomside of the butt 46.

The spring 62 carries a considerable portion of the weight of the hammer52 since the rear end of the spring rests upon the hammer rail 6|. Bythus carrying a substantial portion of the weight of the hammer 52 theamount of pressure between the knuckle 45 and the repetition lever 39 atthe upper extremity of the jack 3l is greatly reduced. This in turnreduces the amount of friction between these elements and furtherabsorbs a substantial portion of the energy of the descending hammer 52.The spring 62 therefore balances out a substantial portion of the weightof the hammer 52 so that the jack 3| when lifted by the whip 23 needonly supply a much lesser amount of power in order to impel the hammer52 against the piano string 53. The construction of the spring G2 issuch that when it is necessary to raise the hammer 52 to a substantiallyupright position in order to make adjustments onV the piano action asfor example adjusting the tension of the spring 43 or adjusting theposition of the button 42, this may readily be accomplished without thenecessity of disconnecting any spring which operation otherwise mightresult in changing the action of the spring.

While the spring 62 balances out a considerable portion of the effect ofthe weight of the hammer 52, enough of the effect of this weight remainsto act against the repetition lever 39 and the jack 3| to producerestoration of the key |6 to the position shown in Fig, 1 uponcompletion of the sounding oi the note.

The combination of the spring 62 and the pivotally mounted knuckle 45produces an action so that when the repetition lever stops at theadjusting screw in the hammer flange or butt flange 41, the jack 3| maygo out in escapelment position and back again without producing amovement of the knuckle 45 on repeated notes.

In the repetition of notes, the knuckle 45 tends to move toward the buttof the hammer so that the jack does not lose contact with the knuckle 45and does not make a full escapement movement, This produces a reductionin the friction in rapid repetition action.

When however the key I6 is struck and held down, the jack goes into fullescapement position, the hammer strikes the string 53 and rebounds onthe repetition lever 39 depressing that lever and the hammer is caughtupon the back check 54. In this action the knuckle 45 is moved by thepoint or upper extremity of the jack toward the hammer in the directionillustrated in Fig. 4 whereupon a full escapement movement is produced.The action is such that the jack is responsible for about one-half ofthe escapement action, and the knuckle is responsible for the rest ofthe escapement action.

The result of the construction just described is such that there is anoticeably greater ease in pressing the keys at slow speed and a greatgain in the operation of the action at a higher speed or repetition ofnotes.

In adjusting and testing the action of the standard grand piano actionsthe action is commonly spoken of as being 50 gram weighted. Such anaction will permit the key I6 to remain depressed if the key is loadedwith a weight of 20 grams. The same action will restore the key I6against a weight of 15 grams. The application of a 60 gram weight to thekey will produce a key action of about 60 times a minute. In contrast tosuch operation a similar piano action constructed in accordance with thepresent invention required a weight of 45 grams on the key I6 in orderto hold the key down. With a weight of 30 grams on the key restorationof the key occurred at a rate of 200 times a minute. With theapplication of a 50 gram force to the key the key was actuated 120 timesa minute.

In a further comparison of the conventional action against an actionconstructed in accordance with the present invention it was found thatwith the application of a certain amount of power it was only possibleto produce a repetition in the conventional action of about 288 fullstrokes per minute whereas in the action embodying the invention 600full strokes per minute were obtained. This then clearly illustrates thedifference in the speed of action which is due to the reduction offriction in the action and the absorption of the inertia energy of thehammer as it rebounds from impact with the piano string.

From the foregoing description and explanation it will become apparentto those skilled in the art that the application of either of theimprovements will produce an improved more sensitive piano action. Thecombination of the two improvements produces the unusual effectsindicated by the weight and speed tests.

While for the purpose of illustrating and describing the presentinvention, a particular embodiment has been shown in the drawing, it isto be understood that the invention is not to be limited thereby sinceobviously such variations in the construction and in their arrangementmay be made as is commensurate with the scope and spirit of theinvention as set forth in the following claims.

What I desire to protect by United States Letters Patent is claimed asfollows:

1. The combination in a grand piano action comprising a hammer buttcarrying on its underside a pivoted knuckle, and a repetition lever andjack arranged to actuate said hammer butt by engagement with saidpivoted knuckle.

2. A grand piano action for the bass section thereof comprising a hammerrail rest having transverse grooves therein, a butt rail carrying a buttiiange connected to a hammer butt, said hammer butt being connected to astem having at the end thereof a hammer, a padded knuckle mounted on theunderside of said hammer butt, and a hammer supporting spring having oneend secured to said hammer butt in the proximity of said knuckle, saidspring having a portion thereof in the proximity of said knuckle woundinto a coil, said spring continuing from said coil in a longitudinaldirection parallel to the hammer stem, the free end of said spring beingmounted in one of the transverse grooves of said hammer rail rest.

3. A grand piano action comprising a hammer rail rest having a pluralityof transverse grooves, a butt rail carrying a butt flange, a hammer buttconnected to a stem supporting a hammer, said hammer butt beingconnected to said butt flange, a knuckle mounted on the underside ofsaid hammer butt for limited pivoted movement with respect thereto, anda hammer supporting spring secured at one end to said hammer butt in theproximity of said knuckle, said spring having a coiled portion locatedin the proximity of said knuckle, said spring extending longitudinallyin a direction parallel to said hammer stem and having the free end ofsaid spring portion mounted in a transverse groove of said hammer railrest.

4. A grand piano action comprising a hammer butt, a knuckle pivotallymounted for limited movement relative to said butt, and a repetitionlever and jack arranged to actuate said hammer butt by engagement withsaid knuckle.

5. In a grand piano action for the bass section having a jack, arepetition lever, and a whip the combination comprising a hammer buttcarrying a hammer, a hammer rest, a knuckle pivotally mounted on theunderside of said butt, a hammer supporting spring carried by said buttand having one end secured thereto adjacent said knuckle and the otherend supported by said rest, and an unweighted piano key for impartingaction to said hammer through said jack, repetition lever and Whip.

6. A grand piano action comprising a hammer rest, a hammer butt carryinga hammer, a knuckle mounted on the underside of said butt for limitedpivoted movement relative thereto, a hammer supporting spring secured atone end to said butt in the proximity of said knuckle, said springhavin-g a coiled portion located adjacent said end and another portionextending longitudinally in the direction of the hammer with the freeend of said spring supported by said rest, a repetition lever, a jack, awhip, and a substantially unweighted key for actuating the hammer andthe interconnecting aforesaid components.

CHARLES F. Sli/HTH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 210,223 Plass Nov. 26, 1878269,405 Gemunder Dec. 19, 1882 1,823,142 Hickman Sept. 15, 19311,900,488 Dasenbrook Mar. 7, 1933 2,411,0054 Schulze Nov. 12, 1946

